Truing device for valve-seats.



PATENTED DEC. 6, 1904.

H. L. MITCHELL.

TRUING DEVICE FOR VALVE SEATS.

unmouron Hun DBO.17, 100a. nnxnwnn 001'. 31. 1004.

. 10 MODEL.

UNITED STATES Patented December 6, 1904.

PATENT OFFICE.

HENRY LAlVEItENCE MITCHELL, OF MARINE CITY, MICHIGAN, ASSIGNOR TO JAMESD. MITCHELL, OF LAKEWOOD, OHIO.

TRUING DEVICE FOR VALVE-SEATS- SPECIFICATION forming part of LettersPatent No. 776,610, dated December 6, 1904.

Application filed December 17, 1903. Renewed October 31, 1904. SerialNo. 230,748. (No model.)

To all; whom it n'mgl concern:

Be it known that I, HENRY LAWERENOE MITCHELL, a citizenof the UnitedStates, residing at Marine City, in the county of St.

Clair and State of Michigan, have invented a certain new and usefulImproved Truing Device t'or Valve-Seats, of which the following is aspecification.

This invention relates to an improved de- IO vice for truing worn,irregular, or defective valve-seats; and it consists of a stem, a truingblade or tool on said stem, centering means, and a means for rotatingthe stem.

The object of the invention is to provide a simple, comparatively cheap,and eflicient valve-seat-truing device in which the truing blade or toolwill be arranged so as to true the seat absolutely central with respectto the valve part which is adapted to seat thereon.

The invention also relates to certain details of construction, all ofwhich will be fully and clearly hereinafterdescribed and claimed,reference being had to the accompanying drawings, in which an adaptationof theinvention 2 5 especially designed for globe-valves is shown.

Figure 1 is a central vertical section through a globe-valve with thetruing device operatively arranged thereon. Fig. .Zis adetached sideelevation of the truing device with a frag- 0 ment of the stem. Fig. 3is a detached side elevation of the truing device looking at rightangles to the View shown in Fig. 2. Fig. 4 is a central longitudinalsection through a fragment of the stem and the truing-blade and theannular screw-threaded combined lockingwasher and guide on line I) b,Fig. 3. Fig. 5 is a central longitudinal section through a frag ment ofthe stem and the truing-blade and the annular screw-threaded combinedlocking- 4o washer and guide on line a a, Fig. 2. Fig. 6 a detached topplan view of the truing de. "vice. Fig. 7 is a detached bottom view ofthe truing device.

In referring to the drawings in detail like numerals designate likeparts.

While in the accompanying drawings I have shown one form of my truingdevice which is especially designed for globe-valves, I desire to statethat the improved device can without any or but slight modification beem- 5 O ployed to true the valve-seats of pump-valves and also all othervalves which have an annular valve-seat, and therefore do not limitmyself to the employment of the truing device in the particular type ofvalve shown and reserve the right to any and all modifications of thesaid device that fairly fall within the scope of thehereinafter-set-forth claims.

The globe-valve shown has a valve-casing 1, having an interior wall 2,provided with an annular valve-seat 3, two oppositely-extending tubularhorizontal connections 4., which are threaded to receive pipe ends, anda vertical tubular extension 5, upon which a capG is screwed. The cap 6has a reduced 5 vertical tubular extension 7, with a packingring 8screwed upon its upper end. The packing-ring 8 is inwardly flanged atthe top, as shown at 9, and suitable packinglO is placed between theflange and the extension 7. 7

The usual valve-stem and valve part are not shown in the accompanyingdrawings, being replaced by parts of the truing device, as will be morespecifically described hereinafter.

In time the annular seat 3 becomes worn or of irregular form, so thatthe valve part cannot be forced tightly against it at all points, whichof course permits the valve to leak and renders it defective. The objectof the invention is to return the valve to perfect condition by truingthe seat, so as to obtain a perfectly llat or plane seat which will becentral with respect to the valve part adapted to seat thereon. Thedevice employed for this purpose consists of (18138111 11, a removable 5socket 12, screwed upon the lower end of the stem and having its lowerend bifurcated or forked to provide spring members 13, which are cutaway on the inner surface, as shown at 1 1, to provide asupporting-recess, a scrrated truing-blade 15, which is fitted in saidrecess between the members 13, and an annular ring 16, which has.acentral circular opening 17, the surrounding wall 18 of which istapered and screw-threaded and adapted to screw upon the outer surfaceof the lower extremity of the members 13, which are correspondinglyscrew-threaded and tapered to draw the members toward each other, andthus rigidly lock the truing-blade in position in the end of the stem.In operating the device the cap of the valve is unscrewed, theValve-stem and valve part are removed, and a stem 11 of similar diameteris inserted in its place in the cap.

A truing-blade 15 of proper length to operatively engage the annularvalve-seat 3 is fitted in the recess formed by the cut-away portions 14:and locked rigidly thereon by the screw-threaded ring 16. The ringis ofproper size to fit snugly in the circular opening in the annularvalve-seat, and thus also serve as a guide for centering the lower endof the stem with respect to the valve-seat.

A valveseat-truing kit of my improved character contains a series ofstems of different diameters, aseries of truing-blades of differentlengths, and a series of annular rings of different sizes, so that atruing device can be assembled to fit and true valve-seatsin varioussizes of valves.

The stem 11 may be rotated by the crank 19 shown or by any otherwell-known means to cause the truing-blade 15 to cut against the face ofthe valve-seat.

The great advantage of this device is that as the stem 11 occupiesexactly the same position as the valve-stem and the ring 16 fits snuglyin the circular opening in the valveseat the seat is trued exactly toreceive the valve part when replaced.

I claim as my invention- 1. In a valve-seat-truing device, a stem havinga portion thereof bifurcated to provide spring members which are cutaway on themner surface to form a recess, a truing-blade fitting in saidrecess and a ring fitting on the lower extremities of the springmembers, substantially as set forth.

2. In a valve-seat-truing device, a stem having a portion thereofbifurcated to provide spring members which are cut away on the innersurface to form a recess, and are exteriorly tapered and screw-threaded,a truingblade fitting in said recess, and a ring screwing on the lowerextremities of the spring members, substantially as set forth.

3. A device for truing annular valve-seats comprising a truing-stem ofsimilar size to the stem of the valve and adapted to be fitted in theplace of said valve-stem; said stem having a bifurcated part at itslower extremity, a serrated truing-blade fitting between the members ofthe bifurcated part and adapted to have cutting engagement with the faceof the annular valve-seat, and a combined lockingring and guide screwingon the lower extremities of the bifurcated members and adapted to fitsnugly in the circular opening in the annular valve-seat, substantiallyas set forth.

a. In a valve-seat-truing device, a stem adapted to be fitted in a valvein place of the valve-stem, a socket screwing on the lower end of thestem and having a bifurcated part, a truing-blade between the members ofthe bifurcations, and an annular ring on the lower end of the socket,substantially as set forth.

HENRY LAWERENGE MITCHELL.

Witnesses:

L. M. SANGSTER, GEO. A. NEUBAUER.

